Bell, being thus convinced, maintains that many of our
facial muscles are "purely instrumental in expression;" or are "a
special provision" for this sole object.[12] But the simple fact
that the anthropoid apes possess the same facial muscles as we
do,[13] renders it very improbable that these muscles in our
case serve exclusively for expression; for no one, I presume,
would be inclined to admit that monkeys have been endowed with
special muscles solely for exhibiting their hideous grimaces.
Distinct uses, independently of expression, can indeed be assigned
with much probability for almost all the facial muscles.

Sir C. Bell evidently wished to draw as broad a distinction as possible
between man and the lower animals; and he consequently asserts that with
"the lower creatures there is no expression but what may be referred,
more or less plainly, to their acts of volition or necessary instincts."
He further maintains that their faces "seem chiefly capable of expressing
rage and fear."[14] But man himself cannot express love and humility
by external signs, so plainly as does a dog, when with drooping ears,
hanging lips, flexuous body, and wagging tail, he meets his beloved master.
Nor can these movements in the dog be explained by acts of volition
or necessary instincts, any more than the beaming eyes and smiling
cheeks of a man when he meets an old friend. If Sir C. Bell had been
questioned about the expression of affection in the dog, he would no doubt
have answered that this animal had been created with special instincts,
adapting him for association with man, and that all further enquiry
on the subject was superfluous.

[12] `Anatomy of Expression,' 3rd edit. pp. 98, 121, 131.

[13] Professor Owen expressly states (Proc. Zoolog. Soc. 1830, p.
28) that this is the case with respect to the Orang, and specifies
all the more important muscles which are well known to serve with man
for the expression of his feelings. See, also, a description of several
of the facial muscles in the Chimpanzee, by Prof. Macalister, in `Annals
and Magazine of Natural History,' vol. vii. May, 1871, p. 342.

Many writers consider the whole subject of Expression as inexplicable.
Thus the illustrious physiologist Muller, says,[17] "The completely
different expression of the features in different passions shows that,
according to the kind of feeling excited, entirely different groups
of the fibres of the facial nerve are acted on. Of the cause of this
we are quite ignorant."

[15] `De la Physionomie,' pp. 12, 73.

[16] `Mecanisme de la Physionomie Humaine,' 8vo edit. p. 31.

[17] `Elements of Physiology,' English translation, vol. ii. p. 934.

No doubt as long as man and all other animals are viewed
as independent creations, an effectual stop is put to our
natural desire to investigate as far as possible the causes
of Expression. By this doctrine, anything and everything can
be equally well explained; and it has proved as pernicious with
respect to Expression as to every other branch of natural history.
With mankind some expressions, such as the bristling of the hair under
the influence of extreme terror, or the uncovering of the teeth under
that of furious rage, can hardly be understood, except on the belief
that man once existed in a much lower and animal-like condition.
The community of certain expressions in distinct though allied species,
as in the movements of the same facial muscles during laughter by man
and by various monkeys, is rendered somewhat more intelligible,
if we believe in their descent from a common progenitor.
He who admits on general grounds that the structure and habits
of all animals have been gradually evolved, will look at the whole
subject of Expression in a new and interesting light.